University of Colorado: Physics 2000: Spectral Lines

Several pages from an excellent site which describe the science of spectroscopy. The unique atomic emission (and absorption) line spectrum of elements are illustrated and explained. Includes a Java applet depicting the quantum energy level changes and the accompanying light emissions and absorbtions; emitted (or absorbed) photon is shown with the appropriate color. Allows for the investigation of the Balmer and Paschen series energy transitions. Includes several other interactive Java applets. Explanations are insightful and written in an easy to understand language which utilizes an intriguing dialogue between a professor and a teen-age student. Well done!